Information recording/reproducing device

ABSTRACT

Contents data that have been enciphered and transmitted are recorded as they are on a recording medium, and the contents key used to encipher these data is enciphered in a way used in this recording system and is recorded on the medium. Moreover, a step is taken to ensure that fine trick plays can be performed. In recording contents data that have been enciphered and transmitted, the contents data themselves are recorded in the enciphered state on the recording medium. However, the contents data are decoded by a contents data decoding circuit  46 , and a map file containing necessary management information for reproduction is created by a map file creating circuit  47  and this file is recorded together with the contents data.

TECHNICAL FIELD

This invention relates to an information recording apparatus, aninformation reproducing apparatus, an information recording andreproducing apparatus, an information recording method, an informationreproducing method, an information recording and reproducing method anda recording medium that enable to transmit and receive data safely.

BACKGROUND ART

In recent years, recording apparatuses and recording media for recordinginformation digitally are spreading. Since, for example, image and musicdata are recorded and reproduced with no deterioration in theserecording apparatuses and recording media, the data can be copiedrepeatedly with the quality of the data maintained. From the viewpointof copyright holders, however, there is a risk that the data thecopyright of which they hold may be repeatedly and fraudulently copiedwith their quality maintained and distributed in the market. For thisreason, it is necessary on the side of recording apparatuses andrecording media to take appropriate measures to prevent copyrighted datafrom being fraudulently copied.

As a system for such copyright protection, in the minidisc (MD)(trademark) system for example a method called SCMS (Serial CopyManagement System) is used. This means information transmitted through adigital interface together with music data. This information shows underwhich of three types of data the music data contained fall: data forfree copy, data copy once allowed or data copy prohibited. Uponreceiving music data from the digital interface, a minidisc recorderdetects an SCMS, and if it is copy prohibited, the music data are notrecorded on the minidisc, and if it is copy once allowed, it is changedinto copy prohibited and is recorded together with the music datareceived, and if it is copy free, it is recorded as it is together withthe music data received.

In this way, in the minidisc system, the SCMS is used to prevent anyfraudulent copy of copyrighted data.

Another method of preventing fraudulent copies of copyrighted data is acontents scramble system used in the Digital Versatile Disc (DVD)(trademark). In this system, all the copyrighted data on a disc areenciphered and only licenced recording apparatuses are given cipher keyswhich enable them to decipher and obtain meaningful data. And recordingapparatuses are designed to ensure that all the operators observe theoperation rules of not making fraudulent copies. In this way, the DVDsystem prevents copyrighted data from being fraudulently copied.

However, according to the system adopted by the minidisc system, thereis a risk that recording apparatuses that do not follow the operatingrule of changing the copy once allowed for the SCMS to the copyprohibited and recording the data received may be manufacturedillegally.

And although the system used by the DVD system is effective in ROMmedia, it is not effective in RAM media in which users can record data.This is because even in cases where unauthorized persons cannot decodethe encryption, an illegal copy of the whole data on the disc into a newdisc can produce a new disc that works on a licensed legitimaterecording apparatus.

Therefore, in the Japanese Patent Application 10-25310 (Japanese PatentApplication 1999-224461 Laid Open on Aug. 17, 1999), information foridentifying individual recording medium (hereinafter referred to as“medium identification information”) are inscribed in it, and thisinformation can only be accessed by licensed apparatuses. In otherwords, the data on each recording medium are enciphered by a mediumidentification information and a key based on a secret obtained bytaking a license, and apparatuses that have not obtained license cannotdecode the data that they may have read making such data meaningless.Furthermore, when a license is given to an apparatus, its operation isprescribed so that no fraudulent copy may be made. Unlicensedapparatuses cannot access medium identification information, and sincemedium identification information varies for each medium, even if a copymay be made by an unlicensed apparatus of all information accessible toit on a new medium, such new medium enables neither unlicensedapparatuses or licensed apparatuses to read information properly.

Meanwhile, the recording apparatus according to the Patent Applicationincludes for example an interface IEEE1394 capable of transmitting andreceiving data to and from other apparatuses and may record contentsdata transmitted from other apparatuses on a recording medium.

In such a case, the contents data may be enciphered and transmitted bymeans of the Digital Transmission Content Protection Standard developedby Sony, Matsushita, Hitachi, Toshiba and Intel (this standard itselfcannot be viewed without obtaining a license, but anybody can obtain aWhite Paper describing its outline from its licensing organization:Digital Transmission Licensing Administrator (DTLA)). The contents dataare enciphered by means of a contents key Kc to be transmitted and thecontents key Kc itself is enciphered. Such a safe method is used fortransmission to the recording apparatuses. The simplest method for therecording apparatus to record on a recording medium the transmitted datasafely, that is, without any fraudulent copy allowed is to record thecontents data enciphered and transmitted as they are on the recordingmedium, and to encipher the contents key used for enciphering these databy means of the method used in this recording system and to record thesame on the recording medium.

In this way, all that a recording apparatus must do at the time ofrecording is to simply receive and record a large volume of contentsdata, and the whole operation is simplified.

However, by the method described above, the contents data remainenciphered while they are transmitted to a recording apparatus andrecorded on a medium, making the reproduction operation inconvenient.

In other words, essentially at the time of reproducing AV contents, inorder to perform trick plays (reproduction while performing a quicktraverse or a quick return), the format and structure of the contentsdata must be identified and it is to be decided which data of therecording medium should be read in response thereto.

However, in the method described above, it is impossible to identifywhich data are recorded in which unit of the recording medium unless thecontents data are read out from the recording medium and decoded, andtherefore to finely control trick plays.

DISCLOSURE OF THE INVENTION

In view of such past problems, it is an object of the present inventionto provide an information recording apparatus, an informationreproducing apparatus, an information recording/reproducing apparatus,as well as an information recording method, an information reproducingmethod and an information recording/reproducing method capable ofrecording contents information on a recording medium and to finelycontrol trick plays of this contents information.

It is another object of the present invention to provide a recordingmedium capable of finely controlling trick plays of the contentsinformation recorded.

It is still another object of the present invention to provide aninformation recording apparatus, an information reproducing apparatus,and an information recording/reproducing apparatus, as well asinformation recording method, an information reproducing method and aninformation recording/reproducing method capable of recording contentsinformation enciphered and transmitted as they are on a recordingmedium, recording information for enciphering this contents informationon a recording medium, and finely controlling trick plays.

It is still another object of the present information to provide arecording medium capable of recording enciphered contents information asit is and finely controlling trick plays of this contents information.

In order to achieve these objects, the information recording apparatusaccording to the present invention includes an inputting means forinputting contents information; a management information creating meansfor extracting the access positions for said contents informationinputted and for creating management information showing one or moreaccess positions for said contents information; and a writing means forwriting said contents information inputted and said managementinformation on a recording medium.

In one respect, the information reproducing apparatus according to thepresent invention includes a reading means for reading contentsinformation and management information showing one or more accesspositions for said contents information from the recording mediumcontaining said contents information and said management information;and a reading position controlling means for controlling the readingpositions of said contents information on said recording medium based onsaid management information read from said recording medium.

In another respect, the information recording/reproducing apparatusaccording to the present invention includes an inputting means forinputting contents information; a management information creating meansfor extracting access positions for said contents information inputtedand for creating management information showing one or more accesspositions for said contents information; a reading means for readingsaid contents information and said management information from saidrecording medium; and a reading position controlling means forcontrolling the reading positions of said contents information on saidrecording medium.

In another respect, the information recording method according to thepresent invention includes the steps of inputting contents information;extracting access positions for said contents information inputted;creating management information showing one or more access positions forsaid contents information; and writing said contents informationinputted and said management information on recording medium.

In another respect, the information reproducing method according to thepresent invention includes the steps of reading said contentsinformation and said management information from a recording medium onwhich contents information and management information showing one ormore access positions for said contents information; and controlling thereading positions of said contents information on said recording mediumbased on said management information read from said recording medium.

In another respect, the information recording/reproducing methodaccording to the present invention includes the steps of during therecording process, inputting contents information, extracting the accesspositions for said contents information inputted, creating managementinformation showing one or more access positions for said contentsinformation, and writing said contents information inputted on therecording medium; and during the reproducing process, reading saidcontents information and said management information from said recordingmedium, and controlling the reading positions of said contentsinformation on said recording medium.

In another respect, the recording medium according to the presentinvention includes contents information, and management informationextracted from said contents information and showing one or more accesspositions for this contents information being recorded.

In another respect, the information recording apparatus according to thepresent invention includes an inputting means for inputting encipheredcontents information; a contents information decoding means for decodingsaid enciphered contents information; a management information creatingmeans for extracting the access positions for said contents informationfrom the contents information obtained by decoding enciphered contentsinformation and for creating management information showing one or moreaccess positions for said contents information; and a recording meansfor recording said enciphered contents information, information forenciphering said contents information as well as said managementinformation created.

In another respect, the information reproducing apparatus according tothe present invention includes a management information reading meansfor reading said contents information, information for enciphering saidcontents information and said management information from a recordingmedium in which enciphered contents information, information forenciphering said contents information and management information showingone or more access positions for said contents information; a readingposition controlling means for controlling the reading positions of saidenciphered contents information and information for enciphering saidcontents information; and a decoding means for decoding said encipheredcontents information based on information for enciphering said contentsinformation.

In another respect, the information recording/reproducing apparatusaccording to the present invention includes an inputting means forinputting enciphered contents information; a contents informationdecoding means for decoding said enciphered contents information; amanagement information creating means for creating managementinformation showing one or more access positions for said contentsinformation; a recording means for recording said enciphered contentsinformation, information for enciphering said contents information, andsaid management information created on a recording medium; a managementinformation reading means for reading enciphered contents information,information for enciphering said contents information and managementinformation showing one or more access positions for said contentsinformation from a recording medium on which said enciphered contentsinformation, information for enciphering said contents information andsaid management information are recorded; a reading position controllingmeans for controlling the reading positions for said enciphered contentsinformation on said recording medium and information for encipheringsaid contents information based on the management information read fromsaid recording medium; and a decoding means for decoding said encipheredcontents information based on the information for enciphering saidcontents information.

In another respect, the information recording method according to thepresent invention includes the steps of inputting enciphered contentsinformation; decoding said enciphered contents information; extractingthe access positions for contents information from said contentsinformation obtained by decoding enciphered contents information;creating management information showing one or more access positions forsaid contents information; and recording said enciphered contentsinformation, information for enciphering said contents information andsaid management information created on the recording medium.

In another respect, the information reproducing method according to thepresent invention includes the steps of reading enciphered contentsinformation, information for enciphering said contents information andmanagement information showing one or more access positions for saidcontents information from a recording medium containing said encipheredcontents information, information for enciphering said contentsinformation and said management information; controlling the readingpositions for said enciphered contents information on said recordingmedium and information for enciphering said contents information; anddecoding said enciphered contents information based on the informationfor enciphering said contents information.

In another respect, the information recording/reproducing methodaccording to the present invention includes the steps of, during therecording process, inputting enciphered contents information, decodingsaid enciphered contents information, extracting the access positionsfor contents information from said contents information obtained bydecoding enciphered contents information, creating managementinformation showing one or more access positions for said contentsinformation, and recording said enciphered contents information andinformation for enciphering said contents information as well as saidmanagement information created; and during the reproducing process,reading enciphered contents information, information for encipheringsaid contents information and management information showing one or moreaccess positions for said contents information from a recording mediumin which said enciphered contents information, information forenciphering said contents information and said management informationare recorded; controlling the reading positions for said encipheredcontents information and information for enciphering said contentsinformation on said recording medium based on the management informationread from said recording medium; and decoding said enciphered contentsinformation based on information for enciphering said contentsinformation.

In another respect, the recording medium according to the presentinvention serve to record enciphered contents information, informationfor enciphering said contents information, and management informationextracted from said contents information and showing one or more accesspositions for said contents information.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing the configuration of an optical discrecording/reproducing apparatus according to the present invention.

FIG. 2 is a drawing showing the overall configuration of data recordedin the optical disc.

FIG. 3 is a block diagram showing the specific configuration of theencryption processing unit in the optical disc recording/reproducingapparatus.

FIG. 4 is a block diagram showing an example of the specificconfiguration of a map file creation circuit of the encryptionprocessing unit.

FIG. 5 is a flow chart showing the operating process of a PAT/PMTanalyzing unit of the map file creation circuit.

FIG. 6 is a conceptual rendering of a random access point list of videodata in the MPEG system.

FIG. 7 is an explanatory schematic diagram of a transport stream and amap file.

FIG. 8 is a block diagram showing an example of specific configurationof a decoding processing unit of the optical disc storing/reproducingapparatus.

FIG. 9 is a block diagram showing an example of another configuration ofthe decoding processing unit.

FIG. 10 is a block diagram showing the configuration of a contents datareproducing apparatus for controlling the readout of contents data bymeans of information contained in the map file.

FIG. 11 is a flowchart showing the operating process of the encryptionprocessing unit when user data are stored in an optical disc.

FIG. 12 is a flowchart showing the analysis process of the streamanalysis unit of the map file creating circuit for analyzing video datatransport packets.

FIG. 13 is a flowchart showing the analysis process of the streamanalysis unit for analyzing audio data transport packets.

FIG. 14 is a flowchart showing the operating process of encryptionprocessing unit when the user data is stored in an optical disc in whichno media identification information DiscID is stored at the time ofmanufacturing.

FIG. 15 is a flowchart showing the reproducing process of user data inthe decoding processing unit.

FIG. 16 is a flowchart showing the reproducing process of user data inthe decoding processing unit.

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode for carrying out the invention is hereinafter explainedwith reference to the drawings.

This invention is applied, for example, to an optical discrecording/reproducing apparatus 10 configured as shown in FIG. 1.

The optical disc recording/reproducing apparatus 10 shown in this FIG. 1includes a spindle motor 12 for rotationally driving an optical disc 11,a recording/reproducing head 13 for optically scanning the informationrecording surface of the optical disc 11, a servo circuit 14 forcontrolling the spindle motor 12 based on reproduction signals obtainedfrom the recording/reproducing head 13, a recording/reproducing unit 15for recording/reproducing data through the optical disc 11 by means ofthe recording/reproducing head 13, and a control circuit 17 forcontrolling the servo circuit 14 and the recording/reproducing unit 15based on setting information inputted from the input operating unit 16.

The spindle motor 12 rotationally drives the optical disc 11 at aconstant linear velocity based on the control of the servo circuit 14.

The recording/reproducing head 13 optically scans the informationrecording surface of the optical disc 11 rotationally driven by thespindle motor 12 to record/reproduce data.

The servo circuit 14 drives the spindle motor 12 so that the opticaldisc 11 may spin at a pre-set speed (for example at a constant linearvelocity) and at the same time controls the tracking, focusing andthreading of the recording/reproducing head 13.

The recording/reproducing unit 15 includes a nencryption processing unit4 and a decoding processing unit 5 operating under the control of thecontrol circuit 17. The encryption processing unit 4 enciphers recordingsignals supplied from the outside, supplies enciphered recording signalsto the recording/reproducing head 13 so that the same may be recorded onthe optical disc 11. And the decoding processing unit 5 decodes thereproduced data that have been reproduced from the optical disc 11 bythe recording/reproducing head 13 and outputs the same as reproducedsignals to the outside.

The input operating unit 16 includes operation buttons not shown infigure, switches, remote controllers and so forth, and outputs signalscorresponding to inputs operated by the user.

The control circuit 17 controls the whole apparatus according to apre-set computer program stored in a memory not shown in figure.

In this mode of carrying out, the optical disc 11 includes, as shown inFIG. 2, a read-in-area AR read in and a data area AR data.

And in the read-in-area AR read in of the optical disc 11, E DiscIDobtained by converting the identification information of the recordingmedium (hereinafter referred to for the sake of convenience as “DiscID”)by a previously prescribed common method in the recording system(hereinafter referred to for the sake of convenience as “enciphered by acommon security of the system”) and an enciphered disc key EKd that hasbeen obtained by enciphering a disc key Kd used for enciphering contentsdata given to each disc by an effective master key Kem created accordingto the medium identification information DiscID allocated to the discare recorded.

Incidentally, the method for converting medium identificationinformation DiscID, i.e. the common security for the system is given bythe copyright holder or a license manager approved by the copyrightholder (for example, a licensor of recording media format) to licenseestogether with the master key Km described below at the time when alicense is granted properly.

For example, one of the methods for converting medium identificationinformation DiscID is to convert the medium identification informationDiscID to information obtained by the time lag at the edge of bitsrepresenting the optical disc information by recording the same based onthe pre-set M series codes. When such a conversion method is used, therecording of the medium identification information DiscID based on thepre-set M series codes and the M series codes become the commonsecurities for the system. For this reason, it will be impossible toread (decode) the medium identification information DiscID unless bothof them are known.

The encryption art based on such M series codes was already proposed bythe present applicant in the Japanese Patent Application 9-288960(corresponding U.S. patent application Ser. No. 09/174,954: filed onOct. 9, 1998 to the U.S. Patent and Trademark Office). Incidentally,this pre-set common security for the system is given to the licenseetogether with the master key Km described below when a proper license isgranted by the copyright holder.

The effective master key Kem is calculated according to the formula (1)by applying a hash function to the combination of the master key Km andthe DiscID.Kem=hash (Km+DiscID)  (1)

Here, the master key Km is a secret key given only to persons (opticaldisc recording/reproducing apparatus) properly licensed by the copyrightholder. In addition, the combination of A and B, when each of themconsists of 32 bits, means combining B after A to make 64-bit data.

And each sector Si (i=1, 2 . . . ) constituting the data area AR data ofthe optical disc 11 consists of a header HD and a main data unit MD. Theheader HD stores a ciphered contents key EKc obtained by enciphering thecontents key Kc used for enciphering contents data by the disc key Kd(the i of Si here means the number of the sector, but the i is omittedwhen it is unnecessary to distinguish individual sectors). The main dataunit MD stores ciphered contents data obtained by enciphering contentsdata by the contents key Kc and received by the recording apparatus.

The encryption processing unit 4 in the optical discrecording/reproducing apparatus 10 of which the concrete configurationis shown in FIG. 3 includes a DiscID encryption decoding circuit 41, aKem generating module 42, a random number generating circuit 43, a Kdencryption decoding circuit 44, a Kc encryption circuit 45, a contentsdata decoding circuit 46, and a map file creating circuit 47.

The DiscID encryption decoding circuit 41 decodes E DiscID read from theread-in-area AR read in of the optical disc 11 by means of therecording/reproducing head 13 based on the common security of the systemkept in the DiscID encryption decoding circuit 41 and creates mediumidentification information DiscID. And this DiscID encryption decodingcircuit 41 receives random numbers generated by the random numbergenerating circuit 43 as medium identification information DiscID,enciphers the same based on the common security of the system asdescribed above to create EDiscID. The EDiscID created from the randomnumbers by this DiscID encryption decoding circuit 41 are recorded inthe read-in-area AR read in of the optical disc 11 through therecording/reproducing head 13.

The Kem generating module 42 includes a Km memory 42A for storing amaster key Km and a hash function circuit 42B for creating effectivemaster keys Kem based on the master key Km and medium identificationinformation DiscID. The hash function circuit 42B generates thecombination of the master key Km and a DiscID according to the formula(1), and applies the hash function to the same to create an effectivemaster key Kem. And the hash function circuit 42B supplies the createdeffective master key Kem to the Kd encryption decoding circuit 44.

The Kd encryption decoding circuit 44 decodes by means of the effectivemaster key Kem the enciphered disc key EKd read from the read-in-area ARread in of the optical disc 11 by the recording/reproducing 13 to createa disc key Kd. And this Kd enciphered decoding circuit 44 receivesrandom numbers generated by the random number generating circuit 43 as adisc key Kd, enciphers the same by means of the effective master key Kemto create an enciphered disc key EKd. The enciphered disc key EKdcreated by this Kd encryption decoding circuit 44 is stored in theread-in-area AR read in of the optical disc 11 through therecording/reproducing head 13.

The Kc encryption circuit 45 enciphers contents keys Kc that has beenreceived from the interface with other apparatuses by means of the disckey Kd to create enciphered contents keys EKc. The enciphered contentskeys EKc created by the Kc encryption circuit 45 are stored in the dataarea AR data of the optical disc 11 through the recording/reproducinghead 13.

The enciphered contents data delivered by the interface unit are storedas they are in the data area AR data of the optical disc 11 through therecording/reproducing head 13.

The contents data decoding circuit 46 decodes contents data by means ofthe contents key Kc and supplies the same to the map file creatingcircuit 47.

The map file creating circuit 47 creates map files containing necessaryinformation at the time of reproduction from the decoded contents data.The map files created by this map file creating circuit 47 are stored inthe data area AR data of the optical disc 11 through therecording/reproducing head 13.

Here, the case in which contents data are MPEG2 transport stream will beexplained with reference to the block diagram in FIG. 4 showing aspecific example of configuration of the map file creating circuit 47.

This map file creating circuit 47 includes a PID filter 472 into whichMPEG2 transport stream on which AV programs are multiplexed is inputtedthrough a terminal 471, a PAT/PMT analysis unit 474 and a streamanalysis unit 475 to which PID transport packets taken out of the PIDfilter 472 are supplied through a switch 473, a counter 476 to which PIDtransport packets taken out of the PID filter 472 are supplied, a mapdata creating unit 477 to which the results of analyses by the PAT/PMTanalysis unit 474 and the stream analysis unit 475 are given, and a filesystem 478 connected to the map data creating unit 477.

The transport stream inputted through the terminal 471 is a stream madeup of consecutive transport packets, and the transport packets arepacketed MPEG2 video streams or MPEG1 audio streams.

The PID filter 472 takes out transport packets of specified PID from theinputted transport packets. The PID is a signal of 13-bit length locatedat the fixed position of the transport packet header, and shows the typeof data stored in the payload (data portion following the transportpacket header).

To begin with, the PID filter 472 takes out transport packets for a PAT(Program Association Table) of which PID=0x0000. The PAT transportpackets outputted from the PID filter 472 are inputted into the PAT/PMTanalyzing unit 474 through a switch 473.

Here, the operating process of the PAT/PMT analyzing unit 474 will beexplained by referring to a flowchart shown in FIG. 5.

At step S1, the PAT/PMT analyzing unit 474 receives PAT transportpackets. PAT contains the PID of transport packets of the PMT (ProgramMap Table) of AV programs multiplexed in the transport stream.

At step S2, the PAT/PMT analysis unit 474 sets the PID of the PMT of AVprograms in the PID filter. After taking out transport packets carryingthe PID of PMT, the PID filter 472 inputs them into the PAT/PMT analysisunit 474.

At step S3, the PAT/PMT analysis unit 474 receives transport packets ofPMT. The PMT contains the PID of transport packets carrying a videostream or an audio stream constituting an AV program as their payloads.PAT/PMT analysis unit 474 acquires the PID of transport packets carryingvideo streams or audio streams constituting AV programs as theirpayloads.

At step S4, the PAT/PMT analysis unit 474 sets the PID of transportpackets carrying a video stream or an audio stream constituting an AVprogram as their payloads in the PID filter and the stream analysis unit475 to end the operating process.

And the PAT/PMT analysis unit 474 gives to the map data creating unit477 the following parameters:

(A) The PID of transport packets of the PMT of an AV program,

(B) The PID of transport packets of video data constituting an AVprogram and the stream_type of the video data.

(C) The PID of transport packets of audio data constituting an AVprogram and the stream_type of the audio data.

(D) PCR_PID of the AV program.

Here, the steam_type means the contents of the PMT, and in the case ofvideo data, it represents the stream-type of MPEG-2/MPEG-1 and in thecase of audio data, it represents the stream-type of MPEG1/AC-3.

And the PID filter 472 takes out the video data transport packets andaudio data transport packets specified by the PAT/PMT analysis unit 474from the input transport stream, and inputs them into the streamanalysis unit 475 through a switch 473. Transport packets other than thevideo data transport packets and audio data transport packets (such asservice information packets) are not inputted into the stream analysisunit.

The transport packets outputted from the PID filter 472 are inputtedinto the counter 476. The counter 476 counts the number of bytes fromthe head packet of the transport stream to be recorded up to the currentpacket and gives the resulting value to the stream analysis unit 475.

The stream analysis unit 475 extracts points that can be accessed atrandom among the AV program for reproduction. The transport packets atthe random access points of video data are packets having the sequenceheader of MPEG video data and the successive I picture data as theirpayloads. A conceptual rendering of the list of random access points isshown in FIG. 6. The random access points show the time stamp oftransport packets to be accessed at random and the addresses forstarting data readout. Here, the time stamp is calculated based on theinput time to the recording apparatus of transport packets at the randomaccess points or the PTS (Presentation Time Stamp) of I pictures at therandom access points. The PTS is information added to the header of PESpackets according to the MPEG2 systems standard. Incidentally, this FIG.6 shows transport stream files in a form of successive recording oftransport packets. But a similar result can be achieved by adding timestamps showing the input time to the recording apparatus of the packetfor each transport packet. This time stamp is similar to the 4-byteTSP_extra_header added to the transport packet prescribed by DV formatfor example.

The random access point information of video data and audio data issupplied to the map data creating unit 477. The map data creating unit477 transforms the random access point information into tables.

The map data creating unit 477 gives the map data tables to the filesystem 478.

The file system 478 creates files out of the map data tables and outputsthem.

FIG. 7 is an explanatory diagram of transport streams and map files. Amap file contains the following data:

1. The PID of transport packets of the PMT of AV programs.

2. The PID of transport packets of video data constituting AV programsand the stream_type of video data.

3. The PID of transport packets of audio data constituting AV programsand the stream_type of audio data.

4. The PCR_PID of AV programs.

5. A list of random access points of AV video data.

6. A list of random access points of AV audio data.

The decoding processing unit 5 in the optical disc recording/reproducingapparatus 10, the specific configuration of which shown in FIG. 8,includes an EdiscId decoding circuit 51, a Kem generating module 52, aKd decoding circuit 54 and a Kc decoding circuit 55.

The EDiscID decoding circuit 51 decodes EdiscID read by saidrecording/reproducing head 13 from the read-in-area AR read in of theoptical disc based on the common security of the system that it has andcreates medium identification information DiscID. This EdiscID creatingcircuit 51 gives the created medium identification information to theKem generating module 52.

The Kem generating module 52 includes a Km memory 52A that stores amaster key Km and a hash function circuit 52 that creates an effectivemaster key Kem from the master key Km and the medium identificationinformation DiscID. The hash function circuit 52B creates thecombination of the master key Km and DiscID according to the formula(1), and applies the hash function thereto to create an effective masterkey Kem. And the hash function circuit 41B supplies the createdeffective master key Kem to the Kd decoding circuit 54. This Kemgenerating module 52 is configured in the same way as the Kem generatingmodule 42, and both may be used for double purposes.

The EKd decoding circuit 54 decodes an enciphered disc key EKd read bythe recording/reproducing head 13 from the read-in-area AR read in ofthe optical disc 11 by means of the effective master key Kem to producea disc key Kd.

The EKc decoding circuit 55 decodes the deciphered contents keys EKcstored in the header of various sectors Si read out by therecording/reproducing head 13 from the data area AR data of the opticaldisc 11 by means of the disc key Kd to calculate a contents key Kc.

Meanwhile, the decoding processing unit 5 shown in FIG. 8 deliverscontents data that have been read out while they remain ciphered and thedecoded contents key Kc to the data interface. This is used for examplewhen these contents are transmitted to other apparatuses. On the otherhand, the decoding processing unit 5 shown in FIG. 9 includes a contentsdecoding circuit 56 that decodes by means of a contents key Kc obtainedby decoding by means of the EKc decoding circuit 55 the encipheredcontents data read by the recording/reproducing head 13 from the dataarea AR data of the optical disc 11 to create clear text contents data.

The decoding processing unit 5 shown in this FIG. 9 is used for examplein case where MPEG and other signals applied to these latter contentsdata in this reproducing apparatus are decoded and outputted as picturesthrough a D/A converter.

Incidentally, for starting this reproducing process, informationcontained in the map files created at the time of recording is used tocontrol by means of the control circuit 17 the readout of contents datafrom the optical disc 11.

FIG. 10 is a block diagram showing the contents data reproducingapparatus for controlling the readout of contents data by means of theinformation contained in map files. Here, a transport stream reproducingapparatus that uses information contained in the map files created inthe map file creating circuit 47 described in FIG. 4 to control thereadout of transport stream files corresponding to the map files will beexplained.

A recording medium 60 contains transport stream files and their mapfiles.

The reproduction control unit 65 instructs the read control unit 61 toread map files. The read control unit 61 reads map files from therecording medium 60. The map files are then processed at the decodingunit 62, the error correction unit 63 and the file system unit 64 to beinputted into the reproduction control unit 65.

The reproduction control unit 65 supplies the PID of PMT transportpackets of AV programs, the PID of transport packets of video dataconstituting the programs, the stream_type of video data, the PID oftransport packets of audio data constituting the programs, thestream_type of audio data and the PCR_PID to a demultiplexer and an AVdecoder not shown.

When an instruction is given from the user interface to proceed to arandom access reproduction, the reproduction control unit 65 determinesthe position of reading data from the recording medium 60 based on thecontents of map data stored inside and inputs random access controlinformation to the read control unit 61. When a program chosen by theuser is to be reproduced from the middle at a certain time, for example,the reproduction control unit 65 finds out the nearest time stamp to thetime specified from the list of time stamps, and instructs the readcontrol unit 61 to read data from an I picture located at the address oftransport stream corresponding to the time stamp. And when a programchosen by the user is to be reproduced at a high speed, the reproductioncontrol unit 65 instructs the read control unit 61 to read successivelyI pictures contained in the program based on data found at the randomaccess point corresponding to the program.

The read control unit 61 reads data from the random access pointdesignated, and the data read and processed by the decoding unit 62, theerror correction unit 63 and the file system unit 64 are outputted astransport stream.

And now the processing procedure at the encryption processing unit 4when user data are to be recorded in the optical disc 11 will beexplained by referring to the flowchart shown in FIG. 11. In this case,however, we assume that the medium identification information DiscID iswritten in the optical disc 11 at the time of the manufacture of theoptical disc 11.

To begin with, at step S11, the DiscID encryption decoding circuit 41receives an EDiscID or medium identification information DiscID that hasbeen read from the read-in-area of the optical disc 11 and enciphered.At step S12, the DiscID encryption decoding circuit 41 further decodesthe EdiscID based on the common security of the system that it has tocreate a DiscID and outputs the same to the hash function circuit 42B ofthe Kem generating module 42. The common security of the system wasgiven by the copyright owner when a proper license was granted.

At step S13, the hash function circuit 42B of the Kem generating module42 reads the master key Km from the Km memory 42A of the Kem generatingmodule 42. And at step S14, the hash function circuit 42B of the Kemgenerating module 42 applies according to the formula (1) the hashfunction to the combination of medium identification information DiscIDof the optical disc 11 and the master key Km to calculate an effectivemaster key Kem and to supply the same to the Kd encryption decodingcircuit 44.

Then at step S15, the Kd encryption decoding circuit 26 receives anenciphered disc key EKd read from the read-in-area of the optical disc11. At step S16, the Kd encryption decoding circuit 26 determineswhether an enciphered disc key EKd is written in the read-in-area of theoptical disc 11 (whether it could receive an enciphered disc key EKd).When it is determined that no enciphered disc key EKd is written, theprocessing advances to step S17 and the random number generating circuit43 generates a d-bit random number, specifically for example a 56-bitrandom number and outputs the same as a disc key Kd to the Kd encryptiondecoding circuit 44.

And at step S18, the Kd encryption decoding circuit 44 enciphers a disckey Kd supplied by the random number generating circuit 43 by means ofan effective master key Kem that has been received from the hashfunction circuit 42B create an enciphered disc key EKd and stores thesame in the read-in-area of the optical disc 11.

When it is determined at step S16 that an enciphered disc key EKd hasbeen written, the processing advances to step S19, and the Kd encryptiondecoding circuit 44 decodes the enciphered disc key EKd that has beenread from the read-in-area AR read in of the optical disc 11 by means ofan effective master key Kem that has been received from the hashfunction circuit 42B to create a disc key Kd. The Kd encryption decodingcircuit 44 outputs the disc key Kd to the Kc encryption circuit 45.

After processing at step S18 or S19, at step S20, the Kc encryptioncircuit 45 receives a contents key Kc and enciphered contents data fromthe interface unit, and at step S21 enciphers the contents key Kc bymeans of a disc key that has been received from the Kd encryptiondecoding circuit 44 (if an enciphered disc key EKd is recorded on theoptical disc 11) or from the random number generating circuit 43 (if noenciphered disc key EKd is recorded on the optical disc 11) to create anenciphered contents key EKc. The Kc encryption circuit 45 also recordsthe enciphered contents key EKc in the sector head that can be found inthe data area of the optical disc 11.

Then at step S22, the contents data are recorded in the main datasection of the data area of the optical disc 11.

At step S23, the contents data decoding circuit 46 decodes encipheredcontents data by using a contents key Kc received from the interface tocreate clear text contents data, which will be delivered to the map filecreating circuit 47.

At step S24, the map file creating circuit 47 (creates new map files ifthere is none and) extracts information required for reproduction fromclear text contents data to add the same to the map files.

Examples of operation of the stream analysis unit 475 of the map filecreating circuit 47 will be explained by referring to the flowchartsshown in FIG. 12 and FIG. 13. FIG. 12 explains the analysis process ofvideo data transport packets, while FIG. 13 explains the analysisprocess of audio data transport packets.

To begin with, the analysis process of video data transport packets willbe explained by referring to a flowchart shown in FIG. 12.

At step S31, the PID of video data of AV programs to be recorded andtheir stream_type are inputted into the stream analysis unit 475 fromthe PAT/PMT analysis unit 404.

At step S32, the stream analysis unit 475 receives video data transportpackets. The stream analysis unit 475 includes a video buffer. Uponreceiving video data transport packets, the stream analysis unit 475inputs the payload into the video stream buffer.

At step S33, the stream analysis unit 475 examines whether any streamcontained in the video stream buffer contains any sequence_header_codeof MPEG video data (32-bit signal of “0x000001B3”). Specifically, thequestion of whether there is anything matching with thesequence_header_code is examined by shifting by 1 byte from the streamhead. Examined bytes is removed from the video stream buffer.

When at step S33 the stream contains no sequence_header_code, theprocessing returns to step S32. When step S32 is repeated twice or more,the video data packet payload is appended to the last data of the videobuffer.

When at step S33 the stream contains any sequence_header_code, at stepS34 transport packets containing the first byte of thesequence_header_code is made to be the starting point for reading Ipicture data for making random accesses.

At step S35, the stream analysis unit 475 informs the starting point forreading the packet to the map data creating unit 477. The number ofbytes counting from the head of the transport stream to be recorded asthe address of random access point to the packet is inputted into themap data creating unit 477 by the counter unit 476, and the PTS(Presentation Time Stamp) of I pictures included in the packet payloadis inputted as the time stamp of the random access point.

At step S36, the stream analysis unit 475 determines whether the currentpacket is the last input packet. If it is not the last packet, theprocessing returns to step S32. If it is the last packet, the processingends.

And now the analyzing process of audio data transport packets will beexplained by referring to FIG. 13.

At step S41, the PID of audio data of programs to be recorded and theirstream_data are inputted by the PAT/PMT analysis unit 474 into thestream analysis unit 475.

At step S42, the stream analysis unit 475 receives audio data transportpackets.

At step S43, the stream analysis unit 475 examines whether its payloadof audio data stream contains any sinc_byte as the first byte of audioframes. Since the audio frame is of a fixed length determined by thecodifying bit rate, the question of whether sync_bytes appearing at thisfixed interval are included in this payload is examined.

If the payload does not include sync_bytes of audio frames at step S43,the processing returns to step S42.

If the payload includes sync_bytes of audio frames at step S43, theprocessing advances to step S44.

At step S44, the stream analysis unit 475 informs the map data creatingunit 477 that this is the starting point for reading audio frames inmaking random accesses to packets including sync_bytes of audio frames.The number of bytes counting from the head of the transport stream to berecorded as the address of random access point to the packet is inputtedinto the map data creating unit 477 by the counter unit 476, and the PTS(Presentation Time Stamp) of I pictures included in the packet payloadis inputted as the time stamp of the random access point.

At step S45, the stream analysis unit 475 determines whether the currentpacket is the last input packet. If it is not the last packet, theprocessing returns to step S42. If it is the last packet, the processingends.

And at step S25 of the flowchart shown in FIG. 11, various circuits ofthe encryption processing unit 4 determine whether all the contents dataare recorded or not. When it is determined that all the contents dataare not yet recorded, the processing advances to step S26, and variouscircuits of the encryption processing unit access sectors that have notrecorded the data of the optical disc 11, returns to step S20 to repeatthe same processing. If it is determined at step S45 that all thecontents data have been recorded, various circuits of the encryptionprocessing unit 4 ends all the recording operation.

By decoding in this way enciphered DiscID by means of the specifiedcommon security of the system given when a proper license was grantedfrom the copyright owner and by obtaining thus medium identificationinformation DiscID, enciphered information is recorded in the recordingmedium.

And now, the operational process in the encryption processing unit 4 bywhich user data are recorded on an optical disc 11 on which no mediumidentification information DiscID was recorded at the time ofmanufacture will be explained by referring to the flowchart shown inFIG. 14.

To begin with, at step S51, the DiscID encryption decoding circuit 21receives an EdiscID read from the read-in-area AR read in of the opticaldisc 11, and the Kd encryption decoding circuit 44 receives anenciphered disc key EKd read from the read-in-area AR read in of theoptical disc 11.

Then at step S52, the DiscID encryption decoding circuit 41 determineswhether an EdiscID is written in the read-in-area AR read in of theoptical disc 11 (whether it was possible to receive EdiscID or not), andthe Kd encryption decoding circuit 44 determines whether an enciphereddisc key EKd has been written in the read-in-area AR read in of theoptical disc 11 (whether it has been possible to receive the enciphereddisc key EKd). When it is determined that neither EdiscID nor enciphereddisc key EKd has been written, the processing advances to step S53, andthe random number generating circuit 43 generates I-bit, specifically128-bit random numbers, and outputs them as medium identificationinformation DiscID to the DiscID encryption decoding circuit 41.

Then at step S54, the DiscID encryption decoding circuit 41 enciphersthe medium identification information DiscID supplied by the randomnumber generating circuit 43 by means of the common security of thesystem that it has, creates an EdiscID and records the same in theread-in-area AR read in of the optical disc 11.

Then at step S55, the hash function circuit 42B of the Kem generatingmodule 42 reads the master key Km from the Km memory 42A of the Kemgenerating module 42. At step S56, according to the formula (1) above,the hash function circuit 42B of the Kem generating module 42 appliesthe hash function to the combination of the medium identificationinformation DiscID of the optical disc 11 and the master key Km readfrom the Km memory 42A to create an effective master key Kem andsupplies the same to the Kd encryption decoding circuit 44.

Then at step S57, the random generating circuit 43 generates d-bit orspecifically 56-bit random numbers and output the same to the Kdencryption decoding circuit 44 as disc key Kd. At step S58, the Kdencryption decoding circuit 44 enciphers the disc key Kd received fromthe random generating circuit 43 by means of the effective master keyKem received from the hash function circuit 42B to create an enciphereddisc key EKd and record the same in the read-in-area AR read in of theoptical disc 11.

If it is determined at step S52 that the EdiscID and the enciphered disckey EKd are written, the processing advances to step S59, and the DiscIDencryption decoding circuit 41 decodes the EdiscID read from thisoptical disc 11 by means of the common security of the system that ithas to create a medium identification information DiscID.

At step S60, the hash function circuit 42B of the Kem generating module42 reads the master key Km from the Km memory 42A of the Kem generatingmodule 42. The hash function circuit 42B of the Kem generating module 42at step S61, according to the formula (1) above, applies the hashfunction to the combination of the DiscID of the optical disc 11 and themaster key Km to calculate the effective master key Kem, and suppliesthe same to the Kd encryption decoding circuit 44.

Then at step S62, the Kd encryption decoding circuit 44 decodes anenciphered disc key EKd read from this optical disc 11 by means of aneffective master key Kem received from the hash function circuit 42B toobtain a disc key Kd. The Kd encryption decoding circuit 44 outputs thedisc key Kd to the Kc encryption circuit 45.

After the processing described at step S58 or step S62, the processingadvances to step S63, and the processing performed at step S63 throughstep S70 are similar to the processing performed at steps S20 throughS27 shown in FIG. 11, and when it is determined that all the contentsdata have been recorded, all the recording operations end.

The medium identification information DiscID is created and recorded inrecording media as described above, and contents data enciphered inresponse to the medium identification information DiscID created and themaster key Km are recorded on the recording medium. For this reason,those who have not been granted a proper license from the copyrightowner or license agents authorized by the copyright owner cannotreproduce contents data copied on existing recording media (recordingmedia on which no DiscID is recorded) as meaningful information.

And now the reproducing process of user data performed by the decodingprocessing unit 5 will be explained by referring to the flowchart shownin FIG. 15. To begin with, at step S81, the EdiscID decoding circuit 51receives enciphered medium identification information DiscID that hasbeen read from the read-in-area AR read in of the optical disc 11 orEdiscID. Furthermore at step S82, the EdiscID decoding circuit 51decodes the EdiscID based on the common security of the system that ithas to create a medium identification information DiscID and outputs thesame to the hash function circuit 52B of the Kem generating module 52.

Then at step S83, the hash function circuit 52B of the Kem generatingmodule 52 receives a medium identification information DiscID outputtedfrom the EdiscID decoding circuit 51, reads the master key Km from theKm memory 52A, applies the hash function to the combination of themedium identification information DiscID of the optical disc 11 and themaster key Km according to the formula (1) to calculate an effectivemaster key Kem, and supplies the same to the EKd decoding circuit 54.

At step S84, the EKd decoding circuit receives an enciphered disc keyEKd read from the read-in-area AR read in of the optical disc 11. Atstep S85 the EKd decoding circuit 54 decodes this enciphered disc keyEKd read by means of the effective master key Kem received from the hashfunction circuit 52B to calculate a disc key Kd and outputs the same tothe Ekc decoding circuit 55.

Then, at step S86, the control circuit 17 reads map files from theoptical disc 11 and uses the same to determine the position for readingcontents data.

At step S87, the EKc decoding circuit 55 receives the encipheredcontents keys EKc of various sectors that have been read from the dataarea AR data of the optical disc 11. At step S88 the EKc decodingcircuit 55 decodes the enciphered contents keys EKc that have been readby means of the disc key Kd received from the EKd decoding circuit 54 tocalculate contents keys Kc and delivers them to the interface unit atstep S89.

At step S90, the contents decoding circuit 56 reads enciphered contentsdata from the data area AR data of the optical disc 11 and delivers themto the interface unit.

Then at step S91, the question of whether various circuits of thedecoding unit 5 have read all the necessary contents data from the dataarea AR data of the optical disc 11. When it is determined that all thecontents data have not yet been read, the process operation advances tostep S92 where various circuits of the decoding unit 5 are supplied withthe data of the following sectors that have not yet been read of theoptical disc 11 and repeats step S86 and the subsequent steps. When itis determined that all the necessary contents data are read, variouscircuits of the decoding unit 5 end the whole reproducing process.

The explanation above relates to, as shown in FIG. 8, process operationsthat take place when contents data that have been read as they areenciphered and the decoded contents key Kc are to be delivered to theinterface unit.

This is used in case where these contents are transmitted to otherapparatuses.

On the other hand, an example of processing in the contents decodingcircuit 56 in which enciphered contents data read by therecording/reproducing head 13 from the data area AR data of the opticaldisc 11 are decoded by means of a contents key Kc decoded by the EKcdecoding circuit 55 to create clear contents data like the one in thedecoding processing unit 5 shown in FIG. 9 will be explained byreferring to the flowchart in FIG. 16.

This is used for example when MPEG and other signals applied to thelatter contents are decoded in this reproducing apparatus to beoutputted as pictures through a D/A converter. Steps S101 through S108in the flowchart shown in FIG. 16 are similar to the processingdescribed at steps S81 through S88 in the flowchart shown in FIG. 15 andtherefore their explanations will be omitted.

At step S109, the contents decoding circuit 56 decodes the encipheredcontents data that have been read from the data area AR data of theoptical disc 11 by means of a contents key Kc supplied by the EKcdecoding circuit 55 to create clear text contents data and outputs thesame for example to an MPEG decoder forming unit of this optical discplayers.

At step S110, various circuits of the decoding unit 5 determine whetherall the necessary contents data have been read from the data area ARdata of the optical disc 11. When it is determined that all the contentsdata have not yet been read, the processing advances to step S111, wherevarious circuits of the decoding unit 5 are supplied with data of thefollowing sectors that have not been read of the optical disc 11 andrepeats step S106 and the subsequent processing. When it is determinedthat all the necessary contents data have been read, various circuits ofthe decoding unit 5 end the whole reproduction processing.

By creating in this way the ID of recording media, enciphering them bymeans of the pre-set common security of the system and recording them ona recording medium, only those who are granted proper license from thecopyright owner or a license manager authorized by the copyright ownerare allowed to access the recording medium.

In the embodiment mentioned above, contents data and enciphered contentskeys Ekc are recorded and reproduced by sector of an optical disc.However, this sector needs not always coincide with the physical sectorof an optical disc and may be within previously fixed limits such asthose formed by combining several physical sectors or logical sectors orlimits set for each recording.

And in the mode of carrying out mentioned above, an enciphered contentskey EKc is to be recorded in the header HD of each sector. However,instead of recording separately in each sector in this way, this may bebundled together and recorded in a lot for example in the read-in-areaAR read in or the data area AR data. Incidentally, when encipheredcontents keys EKc are recorded separately in each sector, they canproduce a stronger enciphering effect.

And in the mode of carrying out mentioned above, one disc key Kd is usedfor each optical disc. On this point, there is no need that it belimited to one. It is possible to use one such disc key in a previouslyfixed block of an optical disc and to use one for each recording.

And in the mode of carrying out mentioned above, map files may beenciphered by means of a contents key or a disc key and may be recordedon an optical disc.

And in the mode of carrying out mentioned above, enciphered contentskeys EKc obtained by enciphering contents keys Kc are recorded on anoptical disc. However, information for creating contents keys Kc may beenciphered by means of a disc key Kd and the result may be recorded on adisc. For example, by applying the hash function to contents keycreating information for creating contents keys Kc, contents keys Kc maybe obtained.

And this invention can be applied to the case in which data are recordedor reproduced on recording media other than optical discs.

INDUSTRIAL APPLICABILITY

With the information recording apparatus, information reproducingapparatus, and information recording/reproducing apparatus as well asinformation recording method, information reproducing method andinformation recording/reproducing method according to the presentinvention, it is possible to record contents information on therecording medium and to finely control trick plays of such contentsinformation.

And with the recording medium according to the present invention, it ispossible to finely control trick plays of contents information recorded.

And with the information recording apparatus, information reproducingapparatus and information recording/reproducing apparatus as well as theinformation recording method, information reproducing method andinformation recording/reproducing method according to the presentinvention, it is possible to record contents information enciphered andtransmitted as it is on the recording medium, to record on the recordingmedium information for enciphering contents information and still tofinely control trick plays of such contents information.

And with the recording medium according to the present invention,enciphered contents information is recorded as it is and furthermore itis possible to finely control trick plays of contents informationrecorded.

1. An information recording apparatus comprising: inputting means forinputting enciphered contents information; contents informationdeciphering means for deciphering the enciphered contents information;access position extracting means for extracting recording medium accesspositions from the deciphered contents information, the recording mediumaccess positions indicating addresses on a recording mediumcorresponding to a time stamp in the contents information; managementinformation creating means for creating management information thatincludes the recording medium access positions from the decipheredcontents information; and recording means for recording the encipheredcontents information on a first area of a recording medium, recordinginformation for enciphering the contents information on a second area ofthe recording medium, and recording the management information on athird area of the recording medium.
 2. The information recordingapparatus according to claim 1 wherein said contents information isinputted in the form of the transport streams prescribed by the MPEG 2systems, and wherein said management information shows the accesspositions for said contents information by means of the time stamps forsaid transport streams and addresses on the recording medium.
 3. Theinformation recording apparatus according to claim 1 wherein, as accesspositions described in the management information, positions whererandom accesses are possible to said contents information are extracted.4. The information recording apparatus according to claim 3 wherein saidcontents information is inputted in the form of the transport streamsprescribed by the MPEG 2 systems; and wherein for the access positionsdescribed in said management information, transport packets eachcontaining a sequence header code are extracted.
 5. An informationreproducing apparatus comprising: reading means for reading contentsinformation and management information from a recording medium, themanagement information including recording medium access positions thatindicate addresses on the recording medium corresponding to a time stampin the contents information; and reading position controlling means forcontrolling the reading positions of the contents information on therecording medium based on the management information read from therecording medium; wherein the contents information is enciphered; andwherein the recording medium access positions are determined from thecontents information.
 6. The information reproducing apparatus accordingto claim 5 wherein said management information shows the accesspositions for the contents information by means of time information ofthe contents information and addresses on the recording medium.
 7. Theinformation reproducing apparatus according to claim 6 wherein saidcontents information is recorded on the recording medium in the form oftransport streams prescribed by the MPEG 2 systems; and said managementinformation shows the access positions for said contents information bymeans of the time stamps of said transport stream and addresses on therecording medium.
 8. The information reproducing apparatus according toclaim 5 wherein, as access positions described in said managementinformation, positions where random accesses to said contentsinformation are available are shown.
 9. The information reproducingapparatus according to claim 8 wherein, said contents information isinputted in the form of transport streams prescribed by the MPEG 2systems; and wherein as access positions described in said managementinformation, transport packets each containing a sequence header codeare shown.
 10. An information recording/reproducing apparatuscomprising: inputting means for inputting enciphered contentsinformation; contents information deciphering means for deciphering theenciphered contents information; access position extracting means forextracting recording medium access positions from the decipheredcontents information, the recording medium access positions indicatingaddresses on a recording medium corresponding to a time stamp in thecontents information; management information creating means for creatingmanagement information that includes the recording medium accesspositions from the deciphered contents information; recording means forrecording the enciphered contents information on a first area of arecording medium, recording information for enciphering the contentsinformation on a second area of the recording medium, and recording themanagement information on a third area of the recording medium; readingmeans for reading the contents information and the managementinformation from the recording medium; and reading position controllingmeans for controlling the reading positions of the contents informationon the recording medium based on the management information read fromthe recording medium.
 11. The information recording/reproducingapparatus according to claim 10 wherein said contents information isinputted in the form of the transport streams prescribed by the MPEG 2systems; and said management information shows the access positions forsaid contents information by means of the time stamps of said transportstreams and addresses on the recording medium.
 12. The informationrecording/reproducing apparatus according to claim 10 wherein, as accesspositions described in said management information, positions whererandom accesses for said contents information are possible areextracted.
 13. The information recording/reproducing apparatus accordingto claim 12 wherein said contents information is inputted in the form ofthe transport streams prescribed by the MPEG 2 systems; and wherein forthe access positions described in said management information, transportpackets each containing a sequence header code are extracted.
 14. Aninformation recording method comprising the steps of: inputtingenciphered contents information; deciphering the contents information;extracting recording medium access positions from the decipheredcontents information, the recording medium access positions indicatingaddresses on a recording medium corresponding to a time stamp in thecontents information; creating management information that includes therecording medium access positions from the deciphered contentsinformation; and recording the enciphered contents information on afirst area of a recording medium, recording information for encipheringthe contents information on a second area of the recording medium, andrecording the management information on a third area of the recordingmedium.
 15. The information recording method according to claim 14wherein, said contents information is inputted in the form of transportstreams prescribed by the MPEG 2 systems; and wherein said managementinformation shows the access positions for said contents information bymeans of the time stamps for said Transport stream and the addresses onthe recording medium.
 16. The information recording method according toclaim 14 wherein, as access positions described in said managementinformation, positions where random accesses are possible for saidcontents information are extracted.
 17. The information recording methodaccording to claim 16 wherein, said contents information is inputted inthe form of the transport streams prescribed by the MPEG 2 systems; andas access positions described in said management information, transportpackets each containing a sequence header code are extracted.
 18. Aninformation reproducing method comprising the steps of: reading contentsinformation and management information from a recording medium, themanagement information including recording medium access positions thatindicate addresses on the recording medium corresponding to a time stampin the contents information; and controlling the reading positions ofthe contents information on the recording medium based on the managementinformation read from the recording medium; wherein the contentsinformation is enciphered; and wherein the recording medium accesspositions are determined from the contents information.
 19. Theinformation reproducing method according to claim 18 wherein, saidcontents information is recorded on a recording medium in the form oftransport streams prescribed by the MPEG 2 systems; and wherein saidmanagement information shows the access positions for said contentsinformation by means of the time stamps of said transport streams andthe addresses on the recording medium.
 20. The information reproducingmethod according to claim 18 wherein, as access positions described insaid management information, positions where random accesses to saidcontents information are possible are shown.
 21. The informationreproducing method according to claim 20 wherein, said contentsinformation is inputted in the form of transport streams prescribed bythe MPEG 2 systems; and as access positions described in said managementinformation, transport packets each containing a sequence header codeare indicated.
 22. An information recording/reproducing methodcomprising the steps of: during the recording process: inputtingenciphered contents information; deciphering the contents information;extracting recording medium access positions from the decipheredcontents information, the recording medium access positions indicatingaddresses on a recording medium corresponding to a time stamp in thecontents information; creating management information that includes therecording medium access positions from the deciphered contentsinformation; and recording the enciphered contents information on afirst area of a recording medium, recording information for encipheringthe contents information on a second area of the recording medium, andrecording the management information on a third area of the recordingmedium; during the reproducing process: reading the contents informationand the management information from the recording medium; andcontrolling the reading positions of the contents information on therecording medium based on the management information read from therecording medium; wherein the contents information is enciphered; andwherein the recording medium access positions are determined from thecontents information.
 23. The information recording/reproducing methodaccording to claim 22 wherein, said contents information is inputted inthe form of transport streams prescribed by the MPEG 2 systems; andwherein said management information shows the access positions for saidcontents information by means of the time stamps of said transportstream and the addresses on the recording medium.
 24. The informationrecording/reproducing method according to claim 22 wherein, as accesspositions described in said management information, positions whererandom accesses to said contents information are possible are extracted.25. The information recording/reproducing method according to claim 24wherein, said contents information is inputted in the form of thetransport streams prescribed by the MPEG 2 systems; and as accesspositions described in said management information, transport packetseach containing a sequence header code are extracted.
 26. A recordingmedium wherein the following are recorded: enciphered contentsinformation, and processor readable management information that includesinstructions for causing the processor to process data stored atrecording medium access positions on the recording medium, the recordingmedium access positions indicating addresses on the recording mediumcorresponding to a time stamp in the contents information.
 27. Theinformation recording apparatus according to claim 1 further comprising:receiving means for receiving, from another device, enciphered contentsinformation and a contents key used to encipher the contentsinformation; and cipher contents key enciphering means for encipheringthe contents key using a medium key; wherein the contents informationdeciphering means deciphers the enciphered contents information receivedfrom the other device; and wherein the recording means records theenciphered contents key on the recording medium as the information forenciphering the contents information.
 28. The information recordingapparatus according to claim 27 further comprising: medium key creatingmeans for choosing the medium key used to encipher the contents keyusing a formula that includes recording medium identificationinformation read from the recording medium.
 29. The informationrecording apparatus according to claim 27 further comprising: medium keycreating means for choosing the medium key used to encipher the contentskey; and master key creating means for choosing a master key used toencipher the medium key by using a formula that includes recordingmedium identification information read from the recording medium. 30.The information recording apparatus according to claim 27 furthercomprising: master key creating means for choosing a master key; themaster key used to encipher the medium key and chosen using a formulathat includes recording medium identification information read from therecording medium; and medium key deciphering means for deciphering themedium key enciphered by the master key; wherein the contents keyenciphering means enciphers the contents key received from the receivingmeans by using the medium key.
 31. The information recording apparatusaccording to claim 1 further comprising: receiving means for receiving,from another device, enciphered contents information and a contents keyused to encipher the contents information; information creating meansfor creating contents key generation information that can be used togenerate the contents key received the receiving means; and contents keygeneration information enciphering means for enciphering the contentskey generation information with a medium key, wherein the contentsinformation deciphering means deciphers the enciphered contentsinformation; and wherein the recording means records the encipheredcontents key generation information on the recording medium as theinformation for enciphering the contents information.
 32. Theinformation recording apparatus according to claim 27 wherein, themanagement information shows the access positions for contentsinformation by means of the time information for contents informationand the addresses on the recording medium.
 33. The information recordingapparatus according to claim 32 wherein, the contents information isinputted in the form of transport streams prescribed by the MPEG 2systems; and the management information shows the access positions forthe contents information by means of the time stamps of the transportstreams and the addresses on the recording medium.
 34. The informationrecording apparatus according to claim 27 wherein, as access positionsdescribed in the management information, positions where random accessesfor the contents information are possible are extracted.
 35. Theinformation recording apparatus according to claim 34 wherein, thecontents information is inputted in the form of transport streamsprescribed by the MPEG 2 systems; and for the access positions describedin the management information, transport packets each containing asequence header code are extracted.
 36. The information reproducingapparatus according to claim 5 wherein: the recording medium contains anenciphered contents keys the contents key is the key used to encipherthe contents information, the information reproducing apparatus furthercomprising a contents key deciphering means for deciphering the contentskey using a medium key.
 37. The information reproducing apparatusaccording to claim 36 further comprising: medium key creating means forchoosing the medium key used to decipher the contents key, the mediumkey chosen using a formula that includes recording medium identificationinformation read from the recording medium.
 38. The informationreproducing apparatus according to claim 36 further comprising: mediumkey deciphering means for deciphering the medium key using a master key;and master key creating means for choosing the master key, the masterkey chosen using a formula that includes recording medium identificationinformation read from the recording medium.
 39. The informationreproducing apparatus according to claim 36 further comprising: masterkey creating means for choosing a master key used to decipher medium keyread from the recording medium, the master key chosen using a formulathat includes medium identification information read from the recordingmedium; and medium key deciphering means for deciphering the medium key.40. The information reproducing apparatus according to claim 5 wherein,the recording medium contains enciphered contents key generationinformation; and further comprising: contents key generation informationdeciphering means for deciphering the contents key generationinformation using a medium key; and contents key generating means forgenerating a contents key using the contents key generation information.41. The information reproducing apparatus according to claim 36 wherein,the management information shows the access positions for contentsinformation by means of the time information of the contents informationand the addresses on the recording medium.
 42. The informationreproducing apparatus according to claim 41 wherein, the contentsinformation is inputted by transport streams prescribed by the MPEG 2systems; and the management information shows the access positions forthe contents information by means of the time stamps of the transportstreams and the addresses on the recording medium.
 43. The informationreproducing apparatus according to claim 36 wherein, as access positionsdescribed in the management information, positions where random accessesare possible for the contents information are extracted.
 44. Theinformation reproducing apparatus according to claim 43 wherein, thecontents information is inputted by transport streams prescribed by theMPEG 2 systems; and wherein for access positions described in themanagement information, transport packets each containing a sequenceheader code are extracted.
 45. The information recording/reproducingapparatus according to claim 10 further comprising: receiving means forreceiving, from another device, enciphered contents information and acontents key used to encipher the contents information; contents keyenciphering means for enciphering the contents key; and contents keydeciphering means for deciphering the contents key by means of a mediumkey, wherein the contents information deciphering means deciphers thecontents information received from the other device; and wherein therecording means records the enciphered contents key on the recordingmedium as the information for enciphering the contents information. 46.The information recording/reproducing apparatus according to claim 45further comprising: medium key creating means for choosing the mediumkey used to encipher the contents key using a formula that includesrecording medium identification information read from the recordingmedium.
 47. The information recording/reproducing apparatus according toclaim 45 further comprising: medium key creating means for choosing themedium key used to encipher the contents key; medium key decipheringmeans for deciphering the medium key using a master key; and master keycreating means for choosing the master key used to encipher the mediumkey, the master key created using a formula that includes recordingmedium identification information read from the recording medium. 48.The information recording/reproducing apparatus according to claim 45further comprising: master key creating means for choosing a master key,the master key used for deciphering the medium key and chosen using aformula that includes recording medium identification information readfrom the recording medium; and medium key deciphering means fordeciphering the medium key using the master key, wherein the contentskey deciphering means deciphers the contents key received by thereceiving means using the medium key.
 49. The informationrecording/reproducing apparatus according to claim 10 furthercomprising: receiving means for receiving, from another device,enciphered contents information and a contents key used to encipher thecontents information; information creating means for creating contentskey generation information information that can be used to generate thecontents key; and contents key generation information enciphering meansfor enciphering the contents key generation information with the mediumkey, wherein the contents information deciphering means deciphers theenciphered contents information; and wherein the recording means recordsthe enciphered contents key generation information on the recordingmedium as the information for enciphering the contents information. 50.The information recording/reproducing apparatus according to claim 45wherein, the management information shows the access positions forcontents information by means of the time information for contentsinformation and the addresses on the recording medium.
 51. Theinformation recording/reproducing apparatus according to claim 50wherein, the contents information is inputted in the form of transportstreams prescribed by the MPEG 2 systems; and wherein the managementinformation shows the access positions for the contents information bymeans of the time stamps of the transport streams and the addresses onthe recording medium.
 52. The information recording/reproducingapparatus according to claim 45 wherein, as access positions describedin the management information, positions where random accesses arepossible for the contents information are extracted.
 53. The informationrecording/reproducing apparatus according to claim 52 wherein, thecontents information is inputted in the form of transport streamsprescribed by the MPEG 2 systems; and wherein for the access positionsdescribed in the management information, transport packets eachcontaining a sequence header code are extracted.
 54. The informationrecording method according to claim 14 further comprising the steps of:receiving enciphered contents information and a contents key used toencipher the contents information; deciphering the contents informationusing the contents key; enciphering the contents key using a medium key;and recording the contents key on the recording medium as theinformation for enciphering the contents information.
 55. Theinformation recording method according to claim 54 further comprisingthe step of: choosing the medium key using a formula that includesrecording medium identification information read from the recordingmedium.
 56. The information recording method according to claim 54further comprising the steps of: choosing the medium key used toencipher the contents key; and choosing a master key used to encipherthe medium key using a formula that includes recording mediumidentification information read from the recording medium.
 57. Theinformation recording method according to claim 27 further comprisingthe steps of: choosing a master key used to encipher the medium keyusing a formula including recording medium identification informationread from the recording medium; deciphering the medium key enciphered bythe master key; and enciphering the contents key using the medium key.58. The information recording/reproducing method according to claim 14further comprising the steps of: receiving enciphered contentsinformation and a contents key used to encipher the contentsinformation; creating contents key generation information that can beused to generate the contents key; enciphering the contents keygeneration with a medium key; deciphering the contents information usingthe contents key; and recording the enciphered contents key generationinformation on the recording medium as the information for encipheringthe contents information.
 59. The information recording method accordingto claim 54 wherein, the management information shows the accesspositions for contents information by means of the time information forcontents information and addresses on the recording medium.
 60. Theinformation recording method according to claim 59 wherein, the contentsinformation is inputted in the form of transport streams prescribed bythe MPEG 2 systems; and wherein the management information shows theaccess positions for the contents information by means of the timestamps of the transport packets and addresses on the recording medium.61. The information recording method according to claim 54 wherein, asaccess positions described in the management information, positionswhere random accesses are possible for the contents information areextracted.
 62. The information recording method according to claim 61wherein, the contents information is inputted in the form of transportpackets prescribed by the MPEG 2 systems; and wherein for the accesspositions described in the management information, transport packetseach containing a sequence header code are extracted.
 63. Theinformation reproducing method according to claim 18 wherein, therecording medium contains an enciphered contents key used to enciphercontents information; and further comprising the step of: decipheringthe enciphered contents key by a medium key.
 64. The informationreproducing method according to claim 63 further comprising the step of:choosing the medium key used to decipher the contents key using aformula that includes recording medium identification information readfrom the recording medium.
 65. The information reproducing methodaccording to claim 63 further comprising the steps of: deciphering themedium key with a master key; and choosing the master key using aformula that includes recording medium identification information readfrom the recording medium.
 66. The information reproducing methodaccording to claim 63 further comprising the steps of: choosing a masterkey for deciphering the medium key read from the recording medium, themaster key chosen using a formula that includes recording mediumidentification information read from the recording medium; anddeciphering the enciphered medium key using the master key.
 67. Theinformation reproducing method according to claim 18 wherein therecording medium contains enciphered contents key generationinformation, the contents key generation information corresponding to acontents key used to encipher the contents information; furthercomprising the steps of: deciphering the contents key generationinformation using a medium key; and generating the contents key based onthe contents key generation information.
 68. The information reproducingmethod according to claim 63 wherein, the management information showsthe access positions for contents information by means of the timeinformation for contents information and addressed on the recordingmedium.
 69. The information reproducing method according to claim 68wherein, the contents information is inputted in the form of transportstreams prescribed by the MPEG 2 systems; and wherein the managementinformation shows the access positions for the contents information bymeans of the time stamps of the transport streams and addresses on therecording medium.
 70. The information reproducing method according toclaim 63 wherein, as access positions described in the managementinformation, positions where random accesses are possible for thecontents information are extracted.
 71. The information reproducingmethod according to claim 70 wherein, the contents information isinputted in the form of transport streams prescribed by the MPEG 2systems; and wherein for the access positions described in themanagement information, transport packets each containing a sequenceheader code are extracted.
 72. An information recording/reproducingmethod according to claim 22 further comprising the steps of: during therecording process: receiving enciphered contents information and acontents key used to encipher the contents information, deciphering thecontents information using the contents key; enciphering the contentskey using a medium key; and recording the contents key on the recordingmedium as the information for enciphering the contents information; andduring the reproducing process: deciphering the enciphered contents keyusing the medium key.
 73. An information recording/reproducing methodaccording to claim 72 further comprising the step of: choosing themedium key using a formula that includes recording medium identificationinformation read from the recording medium.
 74. An informationrecording/reproducing method according to claim 72 further comprisingthe steps of: choosing the medium key used to encipher the contents key;and choosing a master key used to encipher the medium key using aformula that includes recording medium identification information readfrom the recording medium.
 75. An information recording/reproducingmethod according to claim 72 further comprising the steps of: choosing amaster key for deciphering the medium key read from the recordingmedium, using a formula including recording medium identificationinformation read from the recording medium; and deciphering the mediumkey using the master key; wherein the received contents key is aredeciphered using the medium key.
 76. An informationrecording/reproducing method according to claim 22 further comprisingthe steps of: during the recording process: receiving encipheredcontents information and a contents key used to encipher the contentsinformation, creating contents key generation information that can beused to generate the contents key, enciphering the contents keygeneration information with a medium key, deciphering the receivedcontents information using the contents key, and recording theenciphered contents key generation information on the recording mediumas the information for enciphering the contents information; and duringthe reproducing process: deciphering the enciphered contents keygeneration information using the medium key, and creating the contentskey using the contents key generation information.
 77. An informationrecording/reproducing method according to claim 72 wherein, themanagement information shows the access positions for contentsinformation by means of the time information for contents informationand the addresses on the recording medium.
 78. An informationrecording/reproducing method according to claim 77 wherein, the contentsinformation is inputted in the form of transport streams prescribed bythe MPEG 2 systems; and wherein the management information shows theaccess positions for the contents information by means of the timestamps of the transport streams and the addresses on the recordingmedium.
 79. An information recording/reproducing method according toclaim 72 wherein, as access positions described in the managementinformation, positions where random accesses are possible for thecontents information are extracted.
 80. An informationrecording/reproducing method according to claim 79 wherein, the contentsinformation is inputted in the form of transport packets prescribed bythe MPEG 2 systems; and wherein for the access positions described inthe management information, transport packets each containing a sequenceheader code are extracted.
 81. A recording medium wherein the followingare recorded: enciphered contents information, information forenciphering the contents information, and processor readable managementinformation that includes instructions for causing the computerprocessor to process data at recording medium access positions on therecording medium, the recording medium access positions indicatingaddresses on the recording medium corresponding to a time stamp in thecontents information.